The purpose of the study is to examine the impact of worry on the formation of illness representations among individuals newly diagnosed with lung cancer. Worry, the cognitive component of anxiety, is a common subjective experience reported among newly diagnosed cancer patients. Cognitive representations of illness serve to guide adjustment to the illness. Worrying about cancer may negatively affect cognitive processing by biasing perceptions and facilitating the formation of threat-laden illness representations that lead to more anxiety and poorer adjustment over time. There is no research, however, that has examined how worry might influence the content and structure of cognitive representations of illness, which become the foundations for illness adaptation. The study will examine 1) the relationship between worry and the formation of illness representations over time, and 2) the relationship between selected patient and disease factors and worry in persons with cancer. Using two repeated measures, 103 subjects newly diagnosed with lung cancer will be assessed prior to treatment and again 3 months later. Correlational and multiple regression analyses will be used to determine relationships between measures of worry and the cognitive representation of illness, as well as to determine possible covariates. Research findings will contribute new knowledge about how worry influences the formation of illness representations, and will provide the necessary foundation for interventions to improve adjustment in persons with cancer.